Microchip lasers and their applications in optical microsystems

The microchip lasers are the most compact diode pumped solid state lasers. They are fabricated using collective mass production processes, at low cost. Several hundreds of microchip lasers can be fabricated on one single thin wafer of a laser material. The microchip laser is pumped with a standard GaAlAs or GaInAs diode laser, directly or through a multimode fibre. It is a kind of optical transformer which transforms a poor quality laser diode beam to a diffraction limited TEM00 and single frequency laser beam. Moreover, by Q-switching, very short pulses (similar to 0.4-2 ns) with very high peak power (0.5-50 kW) can be obtained. Most of the well known laser materials can be used for emissions near 1, 1.3, 1.5 and 2. Visible and UV emissions are obtained using harmonic generations in non-linear crystals. Microchip lasers have many different industrial applications in large markets such as: automotive, laser marking, environmental and medical applications, public works, telecommunications. They should open the domain of solid state lasers to high volume and low cost markets. (C) 1999 Elsevier Science B.V. All rights reserved.